Internal-combustion engine.



C. E. SARG'ENT.

INTERNAL COMBUSTiON ENGINE.

APPLICATION FlLED JULY 21 I914.

Patented Sept. 12, 1916.

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c. E. SARGENT. INTERNAL COMBUSTION ENGINE.

APPLICATION FlLED JULY 21, 1914. 3]. 1L L w Patented Sept. 12,1916.

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C. E SARGENT.

INTERNAL COMBUSTIQN ENGINE. APPLICATION FILED JULYZI. 19M.

Patented Sept. 12, 1916.

4 SHEETS-SHEET 3.

C. E. SARGENT.

INTERNAL comsusnow ENGINE.

APPLICATION FILED JULY 21,1914.

Patented Sept. 12, 1916.

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" I Z7 zve7z%?i" CAarZm CHLES E. SARGENT, 0F INDIANAPOLIS, INDIANA.

- INTERNAL-GOIVIBU STION ENGINE.

as er To all whom it may concern Be it known that I, CHARLES E. SARGENT, a citizen of the United States, residing at Indianapolis, in the county of Marion and State of Indiana, have invented new and useful Improvements in Internal-Combustion Engines, of which the following is a specification.

My invention relates to certain new and useful improvements in internal combustion engines and is fully described and explained in the specification, and shown in the accompanying drawings, in which Figure 1 is a vertical section through the improved engine. Fig. 2 is a similar section through the cylinder head. Fig. 3 is a view, partly in elevation and partly in longitudinal section, through the hollow piston; Fig. 4 is a similar view through the main piston; Figs. 5 and 6 are horizontal sections on the correspondingly numbered lines of Fig. 1, showing respectively the exhaust and intake ports; Fig. 7 is a fragmentary elevation (partly in section) showing the countershaft, hollow piston, and the connection between the same, this view being generally from the left in Fig. 1; Fig. 8 is a fragmentary elevation of the crank on the countershaft looking from above when the crank is in the position shown in Fig. 7; and Fig. 9 is a diagram illustrating the movement of a typical port-closing notch in the hollow piston with reference to the ports in the cylinder wall.

Referring to the drawings, 10 is the cyl.-

inder. Surrounding its upper end are two annular conduits 11 and 12 for intake and exhaust respectively, these conduits having suitableopenings to the exterior of the engine for the purpose of connecting the intake to the usual source of incoming gas, and the exhaust to the usual exhaust-pipe or mufi-ler. The intake conduit has communication with the interior of the cylinder through ports 13, and the exhaust conduitsimilar communication through ports 14, alternating with the ports 13 and somewhat higher up in the cylinder.

Within the cylinder is a hollow piston 15 provided at its upper end with notches 16 equal in number to the port openings from the cylinder into each of the conduits, that is to say the notches are half as great in numher as the total of intakes and exhaust ports. The notches are spaced at angular distances apart equal to the distance between the ports Specification of Letters Patent. Pamtgntgdl Sept, 12, 19146. Application filed a'ul 'iai, 1914. Serial No. 852,226.

of a given kind, so that when the hollow pis-- t0I1 1S properly positioned the notches can register with, and thus open all of the ports of a given kind. The space between ports of different kinds is substantially equal to the width of the projections, so that a notch can lie just between two dissimilar ports havin line and line contact with each, where by as the hollow piston moves, one kind of port can be opened just as the other is closed. Within the hollow piston is a main piston '17 connected by a pitman 18 with a crank on the main shaft 19.

20 is a countershaft driven from the main shaft at half its speed and provided with a crank-pin 21. In the form of the device here illustrated, the crank-pin is in a plane parallel to the countershaft, but is not itself parallel therewith. The countershaft and its crank-pin are thus mutually perpendicular to the same line, but are not parallel with each other. This is a special form of wabblecrank, which gives correct timing in the structure here illustrated. Some form of wabble-crank forms the simplest possible mechanism for operating the hollow piston of the engine, but the particular structure will vary with the timing desired, and will also be affected by the distance which the countershaft may be 'to one side of its point of connection to the hollow piston. In the present structure, the wabble-crank 21 is connected by a pitman 22 terminating in a ball 23, with a. socket 24 on one side of the hollow piston.

Aside from the ignition mechanism, which is not here illustrated, the foregoing mechanical description includes all the operative parts of the engine, so that I can proceed immediately to describe its operation. For this purpose reference will be had particularly to Fig. 9. The operation of the wabble-crank on the countershaft is to reciprocate the hollow piston vertically, and, in addition, to impart to it an oscillatory movement about the axis of the cylinder, so that any given point in the hollow piston follows a closed curvilinear path which,'when demoment of complete inflammation of the charge; the pointB represents. a point approximately 60 from the end'of the working stroke when the exhaust-port begins to open. The point C represents the close of the exhaust and the commencement of the intake stroke, and the point D the close of the intake and the beginning of the compression stroke.

At the point A- the main piston and the hollow piston are both up, the charge is compressed and fired and the hollow piston is laterally in mid-position..- The explosion forces down the main piston and exerts its force on the upper end of the hollow piston as well, so that a considerable amount of power is actpall received during the working stroke from the hollow piston" and transmitted to the main shaft through the countershaft. During the working stroke, the

main piston moves down, and the hollow piston moves down more slowly, while turning about its axis in the direction of the hands of a,watc h when viewed from above. When the main piston approximates the end of its stroke, say therefrom, the point B is reached, and the exhaust port is opened. The main pistoncompletes its down movement and its upward movement for exhaust, While the hollow piston finishes its downward movement and-swings back to mid-position laterally, as shown at C. It has thus opened and closed the exhaust port in mov-- ing from the point B to G. The main piston then commences its dowhward intake stroke, which it completes while the hollow piston is moving from the point C to the point D, thus opening and closing the intake port. While the main piston is moving up on its compression stroke, the hollow piston moves from D to A, thus keeping both ports closed.

The present structure is peculiarly simple and desirable in its operation. The hollow piston fulfils, in a satisfactory manner, the necessary port-controlling functions of a four-cycle engine, andat the same time cooperates with the main piston to receive the force of explosion and transform it into useful work. The hollow piston, it will be noted, is in constant motion, and it is a wellknown fact in mechanics that less power is required to change the direction of movement of one part slipping on another,- particularly when the surfaces a're lubricated, than is required to start the same part from a position of rest. The frictional losses are, therefore, reduced by the fact that the hollow piston is in constant motion with reference both to the cylinder wall and the main piston at all times, and has not even a momentary period of rest, as has a reciprocating )art. 1 Another point of great importance is that the hollow piston is made relatively thin and preferably of cast-iron. It is wel known that cast-iron expands somewhat when repeatedly heated and cooled. It has been found, in the practical use of an engine proportioned like that here illustrated, that the hollow piston expands in this manner just enough to take up any wear which may occur between it and the cylinder wall. The moment any substantial wear occurs so as to remove the hollow piston from the cooling influence of the cylinder wall, the temperature of the hollow piston, during operation, rises, the extremes of heat and cold to which it is subjected are magnified, and the expansion alluded to takes place, until a tight fit is again established, when the cooling effect of the cylinder wall automatically stops further expansion. 1

Another point of considerable importance is that the oscillating movement of the hollow piston facilitates lubrication. Furthermore, the internal pressure. in the cylinder tends to bend out the projections between the port-controlling notches of the hollow piston, so as to maintain a tight fit. The use of conduits for intake and exhaust extending completely around the cylinder is also ad-- vantageous, since by this means the incoming gases may be heated and the exhaust cooled. It is also possible to adopt the port arrangement illustrated so that the incoming and outgoing gases do not have to make a sharpright-angle turn. a

What I claim as new'and desire to secure by Letters Patent is 1. In combination, two pistons, main and countershafts, connectionsbetween said shafts such that the countershaft moves at half the speed of the main shaft, connections between one piston and the main shaft, a wabble-crank onthe countershaft, connections between the same and the other piston to reciprocate and oscillate the same, Walls inclosing an explosion chamber in which both pistons operate, said hollow piston having its upper end exposed to the pressure of thegases in the cylinder, said walls having angularly spaced ports, and the piston operated by the countershaft having an opening to register successively with said ports as said piston oscillates.

2. The combination of a crank case, a crank shaft, a main piston, a connecting rod, a cylinder having circumferential alternating inlet and exhaust ports, a hollow piston between the 'main piston and cylinder and having spaces which register successively with the cylinder ports, a countershaft, a connecting rod between the hollow piston and countershaft, means for driving the countershaft one-half speed of the engine shaft, and a crank pin on the countershaft at such an angle with the axis of the countershaft that the hollow piston will have a vertical and horizontal movement to cause said spaces to register with said ports.

3. The combination of a crank case, a crank shaft, a main piston, a connecting rod, a cylinder having circumferential alternating inlet and exhaust ports inclined to the axis of the cylinder, a hollow piston between the main piston and cylinder wall containing spaces adapted to register successively with the ports in the cylinder wall, a countershaft, means for driving the countershaft at one-half the speed of the crank-shaft, a crank pin on said counter-shaft at an angle with the axis thereof, a connecting rod be tween the hollow piston and the-crank pin whereby the hollow piston will have both a vertical and rotative motion.

4. The combination of a crank case, a crank shaft, a main piston, a connecting rod, a cylinder having ports radiating from the center, a hollow piston between the main piston and cylinder wall, and having notches in its end which register successively with the ports in the cylinder, the thickness of the hollow piston; wall between the ports being such that the pressure of compression and inflammation will spring the hollow piston shell toward the cylinder wall to prevent leakage, a countershaft, a connecting rod between the hollow piston and countershaft, the countershaft having a crank pin at such an angle with the center line of shaft that a vertical and oscillating motion is given tothe hollow piston.

5. The combination with a cylinder having annular intake and exhaust conduits at its upper end, alternating p'orts communicating with said conduits, the exhaust ports being above the intake ports, of a hollow piston fitting the cylinder, spaces in the hollow piston to register successively with the exhaust and intake ports, a main piston within the hollow piston, a crank shaft, a countershaft gearedthereto to run at half the speed thereof, connections between the main piston and the crank shaft, a crank pin on the countershaft in a non-parallel relation therewithfand a connecting rod connecting the hollow piston with said crank pin, whereby the hollow piston is reciprocated and oscillated thereby and its spaces successively brought into registration with the cylinder ports.

6. The combination of aicrank case, a crank shaft, a main piston, a main connecting rod, a cylinder, a hollow piston vsurrounding the main piston, a counter shaft, a wabble-crank on said counter shaft, a connecting rod between said hollow piston'and said wabble-crank, and a universal joint carried by said connecting rod, and means for driving said counter shaft whereby to oscillate and reciprocate said connecting rod and said hollow piston.

7. The combination of a crank case, a crank shaft, a main piston connected to the crank shaft, a counter shaft, a hollow piston surrounding the main piston, said hollow piston comprising an annular sleeve provided with a plurality of notches therein,

the wall of said hollow piston being so thin that the heat in compression within the cylinder will cause said hollowpiston to engage and bear against the cylinder wall as Wear takes place, and means for reciprocating and oscillating said hollow piston. CHARLES E.-SARGENT. In presence of F. S RonmsoN, F. G. Lama. 

